Enforce CI typechecking for extracted Rig markdown samples

[Copilot]

CI currently exercises samples, but it did not reliably gate on TypeScript validity of the code embedded in skills/rig/samples/*.md. This change makes CI explicitly parse each markdown sample, extract its rig block, and typecheck those extracted programs.

• CI gate for markdown sample type safety

  • Added a dedicated CI step to run only the markdown-sample typecheck suite via:
    • npm run sample -- --testNamePattern="skill markdown samples typecheck"

• Sample typecheck harness now compiles extracted code

  • Updated scripts/run-sample.test.ts to materialize extracted rig snippets as .ts files in a temp directory.
  • Generates a temporary tsconfig.json extending repo config and runs tsc --project ... so extracted snippets are actually compiled.
  • Disables noUnusedLocals and noUnusedParameters in this temp config to avoid false negatives from intentionally minimal sample snippets.

• Sample compatibility cleanup

  • Updated skills/rig/samples/70-multi-file-subagent-summarizer.md to remove deprecated workflow({ output: ... }) usage so it conforms to current workflow typings.

# .github/workflows/ci.yml
- name: Typecheck extracted markdown rig samples
  run: npm run sample -- --testNamePattern="skill markdown samples typecheck"